NetShort
Top pickOur starting recommendation. A larger install at ~104MB, and the catalogue is broad enough that most people find something on the first evening.
What each error message actually means
Most install failures produce one of a small number of messages, and each points at a specific cause. Working through them in order is faster than reinstalling repeatedly.
If the official version of the same app is already on the device, Android refuses to install a differently-signed build over it. Uninstall the existing copy first. Note that uninstalling takes any local app data with it, including a watch history that lives only on the device.
The download did not finish, or the build targets an Android version older than the device supports. Re-download first, since a truncated file is the more common cause of the two.
Usually an architecture mismatch — a build compiled for a different CPU type than the device uses. It can also happen when leftover data from a previous install conflicts. Clearing the app data, or uninstalling and installing cleanly, resolves the second case.
The app updated its server-side checks. A build that unlocked episodes last month can stop doing so without the app itself visibly changing. The fix is a newer build, not a reinstall of the same one.
Check that the file actually finished downloading and is not still in a partial state, and that you are opening the APK rather than a compressed archive containing it.
Frequently asked
Storage is rarely the cause. The usual reason is that a version of the same app signed by a different key is already installed. Uninstall it and try again.
Not normally. Two builds of the same package name cannot coexist, and the modified build shares the package name with the original.
Server-side checks changed. Look for a newer build rather than reinstalling the same one, since the same build will behave the same way.
Where to start
Our pick first, then one of each unlock method.
Our starting recommendation. A larger install at ~104MB, and the catalogue is broad enough that most people find something on the first evening.
One of the lighter installs at ~71MB, from Storymatrix. Quick to try if you are on a metered connection and not sure yet what you like.
From HaloFun, mid-sized at ~78MB. A reasonable second app once you have exhausted a first one.