Hardware & software:
- Amplosion at https://amplosion.app for $1.99 from Andy Ihnatko.
- Tip: User Safari on iOS for iPad when using Google Docs from Andy Ihnatko.
- Apollo App at https://apolloapp.io for free (with in app purchase option) from Rene Ritchie.
- Audio Design Desk at https://add.app for $8.99/month (and up) from Alex Lindsay.