Yes. You can join as an individual and link your bank account to Xiggit. As long as you meet the other eligibility requirements of being 18 years old and a US citizen or permanent resident, you can fully participate in savings, Boost, and the retirement IRA

If you are already contributing to an IRA (Individual Retirement Account), then you will want to ensure your combined contribution amounts (in your Xiggit IRA and in your other IRAs) don't exceed the annual limit.