There are many alternatives to Allo for Android if you are looking for a replacement. The best Android alternative is Joplin. It's not free, so if you're looking for a free alternative, you could try Standard Notes or Google Keep. If that doesn't suit you, our users have ranked more than 100 alternatives to Allo and loads of them are available for Android so hopefully you can find a suitable replacement. Other interesting Android alternatives to Allo are Microsoft OneNote (Freemium), Evernote (Freemium), Simplenote (Free, Open Source) and Raindrop.io (Freemium, Open Source).
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor.