ORLANDO, Fla. -

We’ve all been there. It’s dark outside already.  It’s been a long day at the office and the last thing we want to do is hit the gym or lace up our running shoes. But Melissa Boyink has been staying motivated for the last few months thanks to an smartphone app that pays her when she works out, and fines her when she doesn’t.

“I've been doing it consistently for a couple of months now and I haven't missed a workout,” said Boyink.

It’s called GymPact and it allows users to set up a ‘pact’ that outlines how many days a week they will commit to working out.

The user also sets up how much they will be fined if they miss a day.

Boyink’s pact calls for a four day a week routine, or a fine of $10 a day.

“There was one night specifically where I was like okay it's 10 dollars or you go out and run in the rain, and I went out and ran in the rain, because it's 10 dollars,” she said.

The app pays minimal returns when users meet their pacts, taking money from the couch potatoes that were fined.

Within 6 weeks of using the app, Boyink had earned nearly $10 and had not missed a single workout.

GymPact uses the phone’s GPS location controls to pinpoint when a user is at the gym.

They check in and have to stay at least 30 minutes for the workout to count.

It also syncs with apps like Runkeeper and MapMyFitness for some smartphone users.  

But again, the user has to be doing at least 30 minutes of continuous activity for the workout to count.

If you use a JawBone or FitBit wristband, you can use your steps per day to count towards your pact.

Fitness Instructor Nicole Copare tested out GymPact to see if it was something she’d recommend for her clients, and she found a few shortcomings.

For instance, she said 30 minutes of continuous exercise is not necessary for someone to get a good workout.  If they did 20 minutes or two sets of 20 minute exercise in the same day it would not count.

Also, the app does not allow users to check in or get credit for things like outdoor boot camps or group fitness classes that meet away from a an actual gym.  

A representative from GymPact said that right now iPhone users can get around that by using a feature that tracks continuous motion with the app. 

That tracks a workout even if it is inside the home.

The feature is only available on iPhone right now, and the company did not have a timeframe for when it would be available on other devices.

For Boyink, the biggest drawback is that GymPact does not encourage her to do various types of exercise.