Twenty minutes and a tape measure. You will get a body fat band, an honest week count, and a straight answer about which of my programs fits where you actually are. Two of the possible answers tell you to spend nothing.
If you have been training and eating reasonably and your body is not responding, there are a handful of medical explanations that a program cannot fix and should not paper over. If any of these describe you in the last few months, get labs before you buy anything from anybody.
Not a guess at a percentage. Two observations, in flat morning light, before you eat, standing relaxed and not flexed. Relaxed is the whole point. Anyone can find abs by flexing in a bathroom at 9pm.
Tap either one that is true. Both can be false. That is a normal answer and it is most men.
Tape measure, no shirt, first thing in the morning. Do not suck in. Do not stand up straighter than you normally do. The number is only useful if it is the real one.
The single most common reason a man thinks twelve weeks did nothing is that week one was shot in flattering light and week twelve was shot under a bathroom downlight. Standardise it now and the comparison at the end is evidence instead of a mood.
Front relaxed, back relaxed, and both sides. Arms hanging, not on your hips. Same order each session so you never miss one.
A window on an overcast morning. No overhead spotlight, which carves shadows that read as definition you do not have. Same room, same time.
Before food and before training. Food and water swing how you look more than a week of training does.
Phone propped, not handheld, not angled down. Lock exposure if your phone lets you. Mark the floor with tape so the distance repeats.