John_H

The 2NT bid agrees the trump suit, and indicates you have a minimum expectation of playing in game, and is not 'strict' in terms of shape or count. The bids after 2NT are a matter of partnership style - personally I like ascending cue bids for any slam interest, 3 of the opening suit for sub-par openings, 3NT for 4 card suit openings (won't apply if you play SAYC or other 5 card major systems) and 4 of the opening suit as fairly minimum (<15), shapeless hands. For me, splinter bids suggest a more shapely hand with game possible because of distribution rather than HCP strength, and with the specified shortage as the main feature of interest (less likely to hold AK in a side suit for example).

The extra trump in a passed hand offsets the HCP weakness, but the hand isn't especially good, so 2S is reasonable. The extra strength and shape is in opener's hand and, having now settled on the suit, he/she needs to show more imagination with the rebid. 3C - showing the Ace - would be forcing and make responder's hand look better (KC now looks like it's good). Responder could then bid 4C, rather than 3S, to show a bit extra and the Club control, and then it's down to opener to decide whether to keep exploring or close out in game.

BBO runs in a browser, so any device that happily supports a modern browser (e.g. Chrome, Firefox, latest offerings from Microsoft) will suffice. A more pertinent issue may be the internet connection, and I'd suggest wired where possible (better speeds and higher reliability - less drop outs). Personally, I've used BBO with 2 different flavours of Linux and with Windows 7, all using Firefox as the browser, with no issues.