A couple friends and I have been building a logbook app called Boogie and we just launched a beta version.
Boogie allows you to record a skydive or manually enter one. It taps into your phone's pressure sensor and GPS to get the altitude and location data.
https://play.google.com/store/apps/details?id=io.boogie.boogie
Right now it has limited features / functionality. Here's the website to request a beta invitation.
https://boogie.io/