[New Feature] Requesting for in-app update feature (Auto update notifier)

[Ironfist69]

Describe the new feature you'd like
I propose to add in-app update feature.

Describe the reason why you want to add the feature
I need this feature because users don't have to come to github and download and install the apk manually to update the app.

Describe how to implement the feature if you can

Should look like this
(Concept from JunkFood02/Seal (https://github.com/JunkFood02/Seal)

Additional context
Windows and Android both should have in-app update feature

[mkckr0]

Accept

[mkckr0]

Done at #73.