I have straight talk service and you have to CORRECTLY put in the APN settings or your service won't be complete. I followed the link shown blow exactly and now I can send/receive pic mail and everything works perfect. http://forums.androidcentral.com/google-nexus-5/350688-mms-straight-talk-issue-correct-apn-settings.html
Get Compass Pro, connect to WiFi after downloading to calibrate by turning your GPS on for a while & following app instructions. The Blu has a digital compass or magnetic field sensor so it should work.