The get level method does not parse levels with double type i.e. 0.5. The app crashes at the time of loading. The solution to this issue, is parsing double and then converting it into integer value. e.g. level 0.5 to level 0
The getlevel method does not work for geojson files created without @relations tags. Here is the example of two levels 1 & 2 file:https://gist.githubusercontent.com/akarsh/a92d1c3be234ab1ff7d2469d511ad03a/raw/f483daa278647c5353a784f0081423474cfc7f17/bothlevels.geojson Created using JOSM and following simple indoor tagging.