We choose "we".

Even if you're the sole author of the app/site, the voice of any text should be abstracted away from your identity at least to this small degree. Use "I" only in testimonials, quotes, or in a "message from our founder".

This discipline helps keeps the voice/tone of the text consistent throughout the app, which inspires trust and confidence. It's more polished and professional, especially if you ever contemplate expanding your team.

I think it depends on who is speaking: a team is always a plural, so if it's the team behind X, then you use 'we'; if you're speaking as an individual, you use 'I'. (This can get confusing for some projects, if you're speaking in both capacities while being the only team member.)

So it comes down to how much you want your site associated with you personally, versus having its own identity (and associated "team", even if it's just you on the team).

For hobby projects, I generally go with 'I'; for anything I'm asking for money in exchange for a service, I go with 'we'.

If you feel uncomfortable using 'we' instead of 'I', just file a C-corp and get a registered agent. Now there's two of you, and when you're speaking as the corporation, it's a 'we'. (I'd argue it's always a 'we' for the C-corp, though, because again, it's a team, and teams are always plural.)

Of course, I've been known to use language strangely, so make up your own style rules and go with them.

I would suggest:

Pretigious Technologies takes privacy seriously.

Sounds professional and is "future proof."

"We" is fine. Just ask your dog or cat what they think first.

The problem with "We" is that I've heard it all before ... and it's either BS, or if it isn't, it will eventually be BS (in my evaluation).

I agree, either "I" or a proactive statement of intent: "We guarantee your data is deleted" or along similar lines ...

It's been mentioned in a few articles that a lot of startups try to make themselves be more official and less of a personal touch to be more "professional" and this is generally not helpful.

I would use "I" as long as it is correct.

IMO both are perfectly acceptable.

If you are using a name, like Google, even if that only means one person, then use the name of the app/company.

Gooogle takes your privacy seriously.

"I, Sergei, takes you privacy seriously." Not as convincing.