Classification is tricky because PEDs (iPads) are normally class 1 EFBs, which means they can't be used below 10,000ft.......not much use for an approach or taxi chart! You can get round this by seeing if the Authority would class it as a 2!
However, expect to be required to deactivate 'own ship' position and any GPS function. A small price to pay to get rid of paper Jepps!
GURU on a tablet PC for Perf / Mass and Balance is fine cos its used on the ground pre flight and therefore does not constitute part of the 'EFB'.
Ah, that terminology is now redundant in EASA land, it's all now either "Portable" or "Installed" EFB's, with either Type 'A' or Type 'B' Software...... and it's also now 'T-PED' and 'C-PED' lol....you can now in theory use 'own ship' position (now known as AMMD, or 'Airport Moving Map Display') but that would be subject to getting your CAA to sign off,and the new AMC 20-25 draft has an Appendix to allow you to see what is and isn't possible....As for GURU, Flygprestanda as I understand it are working on an iPad GURU App., and should be along sometime soon (I hope!). I'd be pretty certain that GURU would be classed as a Type 'B' Application on an iPad (or any other tablet for that matter), and therefore subject to the same criteria as other Applications, used as was under the old criteria, yes you may well have had it approved and used as a purely stand alone piece of software, but now, and combined with other Applications on the same hardware device, you have to prove that one Application doesn't affect another, ways of mitigating errors, etc., etc. - you can separate Applications by hard drive partion, but that won't work (as far as i'm aware) on an iOS based system.....
F/o