I got some apps in play store that can help you in hobby I will attach some links https://play.google.com/store/apps/details?id=com.Freeride.Freerider_FREE second link https://play.google.com/store/apps/details?id=appinventor.ai_graham_dyer.CGcalc_v2 third link https://play.google.com/store/apps/details?id=air.airmodelcalc forth linkhttps://play.google.com/store/apps/details?id=be.hcpl.android.sda