diff --git a/app/src/main/java/com/keylesspalace/tusky/AccountFragment.java b/app/src/main/java/com/keylesspalace/tusky/AccountFragment.java
index f5044783a..758a0c5b2 100644
--- a/app/src/main/java/com/keylesspalace/tusky/AccountFragment.java
+++ b/app/src/main/java/com/keylesspalace/tusky/AccountFragment.java
@@ -37,7 +37,7 @@ import java.util.List;
 import retrofit2.Call;
 import retrofit2.Callback;
 
-public class AccountFragment extends Fragment implements AccountActionListener {
+public class AccountFragment extends BaseFragment implements AccountActionListener {
     private static final String TAG = "Account"; // logging tag
 
     private Call<List<Account>> listCall;
@@ -176,25 +176,23 @@ public class AccountFragment extends Fragment implements AccountActionListener {
             default:
             case FOLLOWS: {
                 listCall = api.accountFollowing(accountId, fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case FOLLOWERS: {
                 listCall = api.accountFollowers(accountId, fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case BLOCKS: {
                 listCall = api.blocks(fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case MUTES: {
                 listCall = api.mutes(fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
         }
+        callList.add(listCall);
+        listCall.enqueue(cb);
     }
 
     private void fetchAccounts() {
@@ -264,11 +262,14 @@ public class AccountFragment extends Fragment implements AccountActionListener {
             }
         };
 
+        Call<Relationship> call;
         if (!block) {
-            api.unblockAccount(id).enqueue(cb);
+            call = api.unblockAccount(id);
         } else {
-            api.blockAccount(id).enqueue(cb);
+            call = api.blockAccount(id);
         }
+        callList.add(call);
+        call.enqueue(cb);
     }
 
     private void onBlockSuccess(boolean blocked, int position) {
diff --git a/app/src/main/java/com/keylesspalace/tusky/BaseActivity.java b/app/src/main/java/com/keylesspalace/tusky/BaseActivity.java
index d79421b56..cb0f0dec6 100644
--- a/app/src/main/java/com/keylesspalace/tusky/BaseActivity.java
+++ b/app/src/main/java/com/keylesspalace/tusky/BaseActivity.java
@@ -34,6 +34,7 @@ import com.google.gson.GsonBuilder;
 
 import java.io.IOException;
 
+import okhttp3.Dispatcher;
 import okhttp3.Interceptor;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
@@ -48,6 +49,7 @@ import retrofit2.converter.gson.GsonConverterFactory;
 public class BaseActivity extends AppCompatActivity {
     protected MastodonAPI mastodonAPI;
     protected TuskyAPI tuskyAPI;
+    protected Dispatcher mastodonApiDispatcher;
 
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
@@ -64,6 +66,12 @@ public class BaseActivity extends AppCompatActivity {
         */
     }
 
+    @Override
+    protected void onDestroy() {
+        mastodonApiDispatcher.cancelAll();
+        super.onDestroy();
+    }
+
     @Override
     public void finish() {
         super.finish();
@@ -95,6 +103,8 @@ public class BaseActivity extends AppCompatActivity {
     }
 
     protected void createMastodonAPI() {
+        mastodonApiDispatcher = new Dispatcher();
+
         OkHttpClient okHttpClient = new OkHttpClient.Builder()
                 .addInterceptor(new Interceptor() {
                     @Override
@@ -111,6 +121,7 @@ public class BaseActivity extends AppCompatActivity {
                         return chain.proceed(newRequest);
                     }
                 })
+                .dispatcher(mastodonApiDispatcher)
                 .build();
 
         Gson gson = new GsonBuilder()
diff --git a/app/src/main/java/com/keylesspalace/tusky/BaseFragment.java b/app/src/main/java/com/keylesspalace/tusky/BaseFragment.java
new file mode 100644
index 000000000..c8ccf5a03
--- /dev/null
+++ b/app/src/main/java/com/keylesspalace/tusky/BaseFragment.java
@@ -0,0 +1,43 @@
+/* Copyright 2017 Andrew Dawson
+ *
+ * This file is part of Tusky.
+ *
+ * Tusky is free software: you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License as published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky. If not, see
+ * <http://www.gnu.org/licenses/>. */
+
+package com.keylesspalace.tusky;
+
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import retrofit2.Call;
+
+public class BaseFragment extends Fragment {
+    protected List<Call> callList;
+
+    @Override
+    public void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        callList = new ArrayList<>();
+    }
+
+    @Override
+    public void onDestroy() {
+        for (Call call : callList) {
+            call.cancel();
+        }
+        super.onDestroy();
+    }
+}
diff --git a/app/src/main/java/com/keylesspalace/tusky/ComposeActivity.java b/app/src/main/java/com/keylesspalace/tusky/ComposeActivity.java
index 3b045c182..7e57eb7ac 100644
--- a/app/src/main/java/com/keylesspalace/tusky/ComposeActivity.java
+++ b/app/src/main/java/com/keylesspalace/tusky/ComposeActivity.java
@@ -72,7 +72,6 @@ import android.widget.TextView;
 
 import com.keylesspalace.tusky.entity.Media;
 import com.keylesspalace.tusky.entity.Status;
-import com.squareup.picasso.Picasso;
 
 import java.io.ByteArrayOutputStream;
 import java.io.FileNotFoundException;
@@ -822,12 +821,8 @@ public class ComposeActivity extends BaseActivity {
         LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(side, side);
         layoutParams.setMargins(margin, 0, margin, marginBottom);
         view.setLayoutParams(layoutParams);
-
-        Picasso.with(this)
-                .load(uri)
-                .resize(side, side)
-                .centerCrop()
-                .into(view);
+        view.setScaleType(ImageView.ScaleType.CENTER_CROP);
+        view.setImageBitmap(preview);
 
         view.setOnClickListener(new View.OnClickListener() {
             @Override
@@ -986,20 +981,24 @@ public class ComposeActivity extends BaseActivity {
                     waitForMediaLatch.countDown();
                 } else {
                     Log.d(TAG, "Upload request failed. " + response.message());
-                    onUploadFailure(item);
+                    onUploadFailure(item, call.isCanceled());
                 }
             }
 
             @Override
             public void onFailure(Call<Media> call, Throwable t) {
                 Log.d(TAG, t.getMessage());
-                onUploadFailure(item);
+                onUploadFailure(item, false);
             }
         });
     }
 
-    private void onUploadFailure(QueuedMedia item) {
-        displayTransientError(R.string.error_media_upload_sending);
+    private void onUploadFailure(QueuedMedia item, boolean isCanceled) {
+        if (isCanceled) {
+            /* if the upload was voluntarily cancelled, such as if the user clicked on it to remove
+             * it from the queue, then don't display this error message. */
+            displayTransientError(R.string.error_media_upload_sending);
+        }
         if (finishingUploadDialog != null) {
             finishingUploadDialog.cancel();
         }
@@ -1059,7 +1058,7 @@ public class ComposeActivity extends BaseActivity {
                     MediaMetadataRetriever retriever = new MediaMetadataRetriever();
                     retriever.setDataSource(this, uri);
                     Bitmap source = retriever.getFrameAtTime();
-                    Bitmap bitmap = ThumbnailUtils.extractThumbnail(source, 96, 96);
+                    Bitmap bitmap = ThumbnailUtils.extractThumbnail(source, 128, 128);
                     source.recycle();
                     addMediaToQueue(QueuedMedia.Type.VIDEO, bitmap, uri, mediaSize);
                     break;
@@ -1073,7 +1072,7 @@ public class ComposeActivity extends BaseActivity {
                         return;
                     }
                     Bitmap source = BitmapFactory.decodeStream(stream);
-                    Bitmap bitmap = ThumbnailUtils.extractThumbnail(source, 96, 96);
+                    Bitmap bitmap = ThumbnailUtils.extractThumbnail(source, 128, 128);
                     source.recycle();
                     try {
                         if (stream != null) {
diff --git a/app/src/main/java/com/keylesspalace/tusky/NotificationsFragment.java b/app/src/main/java/com/keylesspalace/tusky/NotificationsFragment.java
index b0cbe28b9..c452ae963 100644
--- a/app/src/main/java/com/keylesspalace/tusky/NotificationsFragment.java
+++ b/app/src/main/java/com/keylesspalace/tusky/NotificationsFragment.java
@@ -161,6 +161,7 @@ public class NotificationsFragment extends SFragment implements
                 onFetchNotificationsFailure((Exception) t);
             }
         });
+        callList.add(listCall);
     }
 
     private void sendFetchNotificationsRequest() {
diff --git a/app/src/main/java/com/keylesspalace/tusky/SFragment.java b/app/src/main/java/com/keylesspalace/tusky/SFragment.java
index 976797c8f..967a0e033 100644
--- a/app/src/main/java/com/keylesspalace/tusky/SFragment.java
+++ b/app/src/main/java/com/keylesspalace/tusky/SFragment.java
@@ -19,9 +19,9 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
+import android.provider.ContactsContract;
 import android.support.annotation.Nullable;
 import android.support.v4.app.DialogFragment;
-import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentTransaction;
 import android.support.v7.widget.PopupMenu;
 import android.support.v7.widget.RecyclerView;
@@ -45,7 +45,7 @@ import retrofit2.Callback;
  * adapters. I feel like the profile pages and thread viewer, which I haven't made yet, will also
  * overlap functionality. So, I'm momentarily leaving it and hopefully working on those will clear
  * up what needs to be where. */
-public class SFragment extends Fragment {
+public class SFragment extends BaseFragment {
     protected String loggedInAccountId;
     protected String loggedInUsername;
 
@@ -103,11 +103,14 @@ public class SFragment extends Fragment {
             }
         };
 
+        Call<Status> call;
         if (reblog) {
-            getApi().reblogStatus(id).enqueue(cb);
+            call = getApi().reblogStatus(id);
         } else {
-            getApi().unreblogStatus(id).enqueue(cb);
+            call = getApi().unreblogStatus(id);
         }
+        call.enqueue(cb);
+        callList.add(call);
     }
 
     protected void favourite(final Status status, final boolean favourite,
@@ -134,15 +137,19 @@ public class SFragment extends Fragment {
             }
         };
 
+        Call<Status> call;
         if (favourite) {
-            getApi().favouriteStatus(id).enqueue(cb);
+            call = getApi().favouriteStatus(id);
         } else {
-            getApi().unfavouriteStatus(id).enqueue(cb);
+            call = getApi().unfavouriteStatus(id);
         }
+        call.enqueue(cb);
+        callList.add(call);
     }
 
     private void block(String id) {
-        getApi().blockAccount(id).enqueue(new Callback<Relationship>() {
+        Call<Relationship> call = getApi().blockAccount(id);
+        call.enqueue(new Callback<Relationship>() {
             @Override
             public void onResponse(Call<Relationship> call, retrofit2.Response<Relationship> response) {
 
@@ -153,10 +160,12 @@ public class SFragment extends Fragment {
 
             }
         });
+        callList.add(call);
     }
 
     private void delete(String id) {
-        getApi().deleteStatus(id).enqueue(new Callback<ResponseBody>() {
+        Call<ResponseBody> call = getApi().deleteStatus(id);
+        call.enqueue(new Callback<ResponseBody>() {
             @Override
             public void onResponse(Call<ResponseBody> call, retrofit2.Response<ResponseBody> response) {
 
@@ -167,6 +176,7 @@ public class SFragment extends Fragment {
 
             }
         });
+        callList.add(call);
     }
 
     protected void more(Status status, View view, final AdapterItemRemover adapter,
diff --git a/app/src/main/java/com/keylesspalace/tusky/TimelineFragment.java b/app/src/main/java/com/keylesspalace/tusky/TimelineFragment.java
index fff484cb7..cd8e12a38 100644
--- a/app/src/main/java/com/keylesspalace/tusky/TimelineFragment.java
+++ b/app/src/main/java/com/keylesspalace/tusky/TimelineFragment.java
@@ -193,30 +193,27 @@ public class TimelineFragment extends SFragment implements
             default:
             case HOME: {
                 listCall = api.homeTimeline(fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case PUBLIC: {
                 listCall = api.publicTimeline(null, fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case TAG: {
                 listCall = api.hashtagTimeline(hashtagOrId, null, fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case USER: {
                 listCall = api.accountStatuses(hashtagOrId, fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
             case FAVOURITES: {
                 listCall = api.favourites(fromId, uptoId, null);
-                listCall.enqueue(cb);
                 break;
             }
         }
+        callList.add(listCall);
+        listCall.enqueue(cb);
     }
 
     private void sendFetchTimelineRequest() {
diff --git a/app/src/main/java/com/keylesspalace/tusky/ViewThreadFragment.java b/app/src/main/java/com/keylesspalace/tusky/ViewThreadFragment.java
index 1dfaad1d9..11120541b 100644
--- a/app/src/main/java/com/keylesspalace/tusky/ViewThreadFragment.java
+++ b/app/src/main/java/com/keylesspalace/tusky/ViewThreadFragment.java
@@ -79,7 +79,8 @@ public class ViewThreadFragment extends SFragment implements StatusActionListene
     private void sendStatusRequest(final String id) {
         MastodonAPI api = ((BaseActivity) getActivity()).mastodonAPI;
 
-        api.status(id).enqueue(new Callback<Status>() {
+        Call<Status> call = api.status(id);
+        call.enqueue(new Callback<Status>() {
             @Override
             public void onResponse(Call<Status> call, retrofit2.Response<Status> response) {
                 if (response.isSuccessful()) {
@@ -95,12 +96,14 @@ public class ViewThreadFragment extends SFragment implements StatusActionListene
                 onThreadRequestFailure(id);
             }
         });
+        callList.add(call);
     }
 
     private void sendThreadRequest(final String id) {
         MastodonAPI api = ((BaseActivity) getActivity()).mastodonAPI;
 
-        api.statusContext(id).enqueue(new Callback<StatusContext>() {
+        Call<StatusContext> call = api.statusContext(id);
+        call.enqueue(new Callback<StatusContext>() {
             @Override
             public void onResponse(Call<StatusContext> call, retrofit2.Response<StatusContext> response) {
                 if (response.isSuccessful()) {
@@ -118,6 +121,7 @@ public class ViewThreadFragment extends SFragment implements StatusActionListene
                 onThreadRequestFailure(id);
             }
         });
+        callList.add(call);
     }
 
     private void onThreadRequestFailure(final String id) {