Groupme app is not yet in the pc/laptop market but you can use it with the help of emulators like bluestacks. How to Download GroupMe for PC Windows Xp 7 8.1 :

Create separate URL for each group you make.You can create your own group of friends and remove them anytime.Well optimized for Smartphones and Tablets of all ranges.Text messaging service in real-time group for mobile phones.It is free to use, but you could incur charges from your provider SMS.It also provides several commands in its FAQ page to help you manage smoothly group texting. You can create any number of groups and each group receives a unique phone number.The tool works on all mobile phones Android, Mac, windows. You can even call that number to start a conference call with members of their group. Friends can be easily added or removed from a group,best thing is that you can keep everything organized. Once this is done, GroupM sends you a phone number that can be assigned to a group and used to send text messages. GroupMe is a tool of mobile group text messaging in real time that helps you easily communicate with a group of people via text messages on your cell phone.You must enter your telephone number you register for a free account.