Hardware & software:
- IPhone Battery Cases for various $ (Amazon Affiliate Link) from Rene Ritchie.
- Spectre Camera (iOS) at https://spectre.cam for $2.99 from Andy Ihnatko.
- TextMate 2.0 at https://macromates.com for free from Leo Laporte.
- MyNoise (iOS) for free from Lori Gil.