Completely agree with the point that the managers are the target audience. People use all kinds of poorly-designed an inconvenient software at work because they're forced to by their boss are the company IT department. Well-designed software is already a leg up, but only if you can properly sell it to the correct decision makers and make it easy for them to switch over.
This app wasn't inherently flawed — if it had started to get traction from a couple companies using it, then word-of-mouth spread because of how easy the app was to use, it could have gone a lot better. I can imagine my friends who are management consultants using this to keep track of all the expenses they're playing on the company card or billing the client.