I'm still not entirely clear if Pete's folks actually funded the app, or just did business with the company that dev'd it, honestly. The latter actually wouldn't be much of an issue, since from what I understand not terribly many people are particularly interested in sticking their dick in the overclocked cheese grinder that is software development for election infrastructure, i.e. it's easy-ish to have done business with them just due to limited options. The former might even not be anything but a bad look -- other campaigns, including bernie's, largely seems to be suggesting the official numbers starting to ooze out are in line with what folks were seeing on the ground, i.e. whatever problems the app had was just plain ol' rush job development crap. Pete just performing well in an area he hyper focused on, in a way to produce specific results, is a non-story that doesn't require any shadowy (heh) shenanigans (a non-story we'll no doubt see blown up into mounds of conspiratorial media buzz, of course).
Beyond Iowa, policy wise Pete's, like... actually fine? His platform and rhetoric are largely left-wing (shit, in some places more aggressively than sanders, iirc) and whatnot. Miles better than trump, probably even as good or better than biden. When it comes to other stuff, though... oof. That falsifying black endorsements thing is basically a case in point. His record as a mayor has some nasty shit in it, too. Folks that dislike pete for non-bigot reasons definitely have grounds to do so.