Yes, Radiocrafts offers a trial subscription together with the RC16xxxx-SIG Demonstration Kit.
It includes: One year platinum level subscription (platinum subscription comprises of 140 uplink and 4 downlink messages / day during 1 year starting from the activation date).
Otherwise, for application prototyping, you have to contact your local SIGFOX Network Operator (SNO) who will make you a subscription offer. For example, French SNO is offering a developer package of 20 platinum level subscriptions at 250€ to support development purposes.
Last Update: August 8, 2017