Scrambled EXIF - the simplest upgrade to removing meta data from your photos, when you want to send them to people
FFShare - the simplest upgrade to removing metadata from your photos/videos AND compressing them when you send or share them with someone. This saves on upload time (upload speeds are often horrible) and bandwidth for both sender and receiver.
Saber - handwriting notes app for Android
DiskUsage - disk space analyser and visualiser, with nothing better IMHO
RootlessJamesDSP - want systemwide Viper4Android but without rooting? This thing needs you to have a degree in audio engineering (lol jk). AutoEQ presets, DSP, convolver, virtual room effects, a crazy equaliser, +15 dB volume gain, its got a bunch of stuff you can customise separately for your phone speakers, different headphones and other connected audio gear.
(yes I might eventually have a long list to update the smartphone guide with solid recommendations)
(yes I might eventually have a long list to update the smartphone guide with solid recommendations)