You know such an application? :-). I hear from time time statements like: "This is just a report - so I don't need transactions - I'm only reading the data". In this particular case you would access the database without a defined transaction and especially isolation - so you will basically see a snapshot of the database (especially uncommitted changes).
Even if you totally ignore the transactions - you will still get the "Green Bar" in most cases. This is probably the reason, why transactions are often in fact ignored ...until the production :-).