JumpToken (JMPT) is a special currency that is used to pay for tasks completed on JumpTask. In the case of Honeygain, you can receive your earnings in JumpTokens (as opposed to Honeygain credits) if you switch to JumpTask mode on your Honeygain account.
There’s a variety of benefits to using JumpToken instead of Honeygain credits. You can read more about them here.
General information on how to enable JumpTask mode on your Honeygain account can be found here.