PA28 pilot believes he may have entered BOS Class B airspace while attempting to navigate with a laptop-based EFB with GPS input.

Narrative

I was flying over Needham (VPNED) at 2;800 under the Class B airspace in Boston. After a bit of sightseeing it was time to return home. It was hazy and the sun was going down. I called Boston Approach for flight following and proceeded southwest. I decided to climb to 3;500 as the floor of the Bravo in this area was at 4;000. My route took me a very very small amount into the corner of the Bravo where the floor is 3;000. I noticed this and immediately turned away from the Bravo and exited. I then proceeded direct and landed. The Controller did not mention anything and I may not have even touched Bravo airspace. I had a laptop running EFB software as well as my GPS and was spending time scrolling the map around to find the floor of the airspace all the while I was flying into it (potentially). Working with the technology was a factor. I was also tired from the previous night and the day of flying. Rather than impromptu flying; I am going to plan future flights better to know exactly where I am going rather than rely on technology with user interfaces which require lots of time to manipulate while flying.