It was a lovely stay for us in Rome. App is close to Termini central station, less than 5 min walking, close to supermarket, close to restorants where you can eat good, for "normal" price's.
In the app there is a fully equiped kitchen with everything that you need, bathroom quite small )especialy shower cabin), but clean.
Enterier of app is quite charming and interesting.
From there is no more than 15 min walking to Colloseum, and from there you are almost everywhere in central Rome(pantheon, trevi plaza spagna, plaza popolo etc etc..., so if you are fan of walking you can see almost everything by foot.
Overall, great experience, more than worth for money.