I agree with answer given by GST Payer. There are many GST return filing software.
More than 40 companies have registered as GSP and this list is ever increasing. So with a simple calculation you will find more than 40 GST return filing software.
But question is do you really need a software to file GST return?
In my opinion, companie with huge transaction volume should use a software. As on writing this answer it makes sense to use GST return filing software.
But as we can guess from recent meetings, GST council is serious on making GST return filing an easy process.
Soon we will have a single return instead of 3 returns.
In single return we will be required to provide details of sales and purchases which are currently provided in GSTR-1 and GSTR-2 separately.
Once this is done, we will not have to worry about matching exercise, GST server will automatically match purchase invoices with suppliers data and give any mismatch.
Currently we are concerned about time consumed in matching of purchase invoices, this activitiy will be taken care by GST server itself.
So, I can say do not use any software for time being, still if you need one then go for Winman GST. It is free for time being.
After return are made simple, this will be done shortly, you will not require any software.
We were doing same thing in Karnataka, we had to upload sales and purchase invoice details and system used to match them. We never required any software here under VAT, so I don't think we will require any software under GST also.
All these GSP will find it tough to sell their software for indirect taxes as most of them will become irrelevant and competition will be high. Don't go with marketing tactics. GST will be Good and Simple tax in very short time.
Don't use any software. If you still want to use go with WINMAN GST software, I use it for few clients, it's easy to use.
But in long run once it starts charging I will stick to offline utilities, anyhow within few months we will have very simple returns and most of processing and time consuming tasks will be done directly by GST servers.