It's not about intent, it's about perception. Using or building a tit-staring app may or may not imply that the guy in question respects women less for their technical merits, or judges them on looks rather than skills.
The problem is that as a technical woman in the audience, you will be very likely to perceive such an initiative as something that detracts from your personal values (professional merit, technical skills). This is doubly true in the tech community, where women are a minority, and is separate from the question of whether technical guys actually disrespect women. This kind of initiative is bad regardless. I'm pretty sure, though, that you will find a correlation between tit-staring and actual discrimination. Women as a minority in technical communities already have a hard enough time coping with the pressure to perform "in spite of their gender", there is no point in making it tougher for them.
When we use words like "objectification" in the context of sex discrimination in tech, it's really just an abstraction over valuing women less than men regarding technical skills. A lot of smart people will consider this a weasel-word, but it has a foundation in actual social mechanisms.