The plaintiffs claim Sirin Labs, Stox and Leadcoin didn't fulfill product promises to investors.
The head of blockchain smartphone startup Sirin Labs, was sued over unpaid bills.
Israel-based Sirin Labs has laid off a quarter of its workforce, saying sales of its Finney phone are lower than expected.
Sirin Labs, developer of the Finney blockchain phone, has teamed up with MyEtherWallet for an integration aimed to benefit both companies.