If you are a photography enthusiast (as most members of our team are) 500px is probably one of your favourite places on the web. And they also have an amazing 500px iPad app, which is also the SmashApp of the Day.

So, today we have a real treat for you – we are continuing our series about the apps loved by CEOs with an interview with Evgeny Tchebotarev and Oleg Gutsol, founders of 500px, in which they let us peek into their iPhones and see the apps they use everyday, games they like to play and their favourite apps which help them stay organized.

The first question, as always, was to list their three favourite apps. Both included Flipboard on the list, but it seems that the co-founders have slightly different taste here – Oleg apparently loves reading so he chose iBooks, while Evgeny prefers relaxing with the sound of radio so he chose TuneIn Radio. Oleg’s list wouldn’t be complete without Things (you’ll see why later) and it was probably Evgeny’s busy lifestyle that made him realize how cool Hotel Tonight is.

The last app they installed on their smartphones (apart from the testing 500px app) and Angry Birds Space (obviously) was W.E.L.D.E.R word app, although Evgeny admits he hasn’t played it yet.

Both Evgeny and Oleg are big fans of productivity apps and Oleg honestly admitted:

‘It probably sounds boring, but I love productivity apps and I always enjoy seeing a great new solution to the task management problem’

And then he started praising Things – it is not just on his list of favorite apps, but he also thinks it is the most useful app because it ‘let’s me stay organized daily’ and this is the app he’d recommend for work. Evgeny had no other option than to agree and he added:

‘Even at a steep price of $10 it is well worth the money for to-do obsessed people like us.’

In order not to make this interview all about how great Thins app is, he added a couple more productivity apps he loves, such as Mint and iTunes U. Depending on the day (or morning, to be more precise) the first app he taps when he wakes up is Twitter, Mail or Flipboard and at that point Oleg intervened and simply said: ‘For me, it’s always Mail’.

But although these two guys made some really amazing things they are not just about work. They like to play, too.  Oleg told us that for him, games like Angry Birds, Fruit Ninja and the like are great ways to relax and when we asked him about his favourite game he said:

‘There are two games actually: Machinarium and Sword & Sworcery. These games are amazingly well done with a great attention to graphics and sound, which creates a truly unique experience.‘

For a visual type of person, Evgeny surprised us and chose a musical game as his favourite.

‘I really enjoyed Groove Coaster — a musical game, because it has great music and allows you to be part of it. Really awesome.‘

And then, for the end of the interview, he gave us a great tip about which games you should have on your phone at any time:

‘I’d recommend Gesundheit! game for interesting graphics, and Where’s My Water? game in case you encounter kids — that is a great game that sucks them in for hours.‘

Make sure you check 500px app, especially the new update which is due make its appearace in the iTunes AppStore really soon with retina graphics and even sharper images and enjoy photography on your iPad.

As for Smashapp, the series of interviews in which the creators of best apps reveal what apps they can’t live without continues. So, stay tuned for the next interview. In the meantime, enjoy the coolest apps for iPhone, iPad and Android.

Happy Holidays!