App-Based Certified Diabetes Education Therapy (AB-CDE)

Inclusion Criteria: 1. Diagnosis of type 1 diabetes mellitus for at least 1 year. 2. Age 18 years and older. 3. Able to read, write and understand spoken English 4. HbA1c or GMI 7.5- 11.5% at screening. GMI (%) = 3.31 + 0.02392 × \[mean glucose in mg/dL\] based on prior 30 days of CGM data with at least 70% time CGM active\[6\] 5. Use of multiple daily insulin injections (MDI) for at least 30 days at the time of screening visit. 6. Willing to use the approved study insulin and devices while on study - Humalog and Basaglar Tempo pens, Dexcom G6 CGM, study iPhone, Apple watch 7. Willingness and ability to independently follow all study procedures, including attending all clinic and DSMES and behavioral health visits. 8. Total daily insulin requirements of less than 200 units Exclusion Criteria: 1. Female of childbearing potential who is pregnant or intending to become pregnant or breast-feeding or is not using adequate contraceptive methods. Acceptable contraception includes birth control pill / patch / vaginal ring, Depo-Provera, Norplant, an IUD, the double barrier method (the woman uses a diaphragm and spermicide, and the man uses a condom), or abstinence. 2. History of stroke, heart failure, myocardial infarction, angina pectoris, or coronary arterial bypass graft or angioplasty. 3. Renal insufficiency (GFR \< 60 ml/min, using either MDRD\*\* or CKD-EPI# equation as reported by the laboratory). 4. Liver failure, cirrhosis, or any other liver disease that compromises liver function as determined by the investigator. 5. History of severe hypoglycemia during the 3 months prior to screening or hypoglycemia unawareness as judged by the investigator. Participants will complete a hypoglycemia awareness questionnaire. Participants will be excluded for four or more R responses. 6. History of diabetes ketoacidosis during the 3 months prior to screening, as diagnosed on hospital admission or as judged by the investigator. 7. History of psychiatric admission during the 6 months prior to screening. 8. Adrenal insufficiency. 9. Any active infection. 10. Known or suspected abuse of alcohol, narcotics, or illicit drugs. 11. Uncontrolled seizure disorder. 12. Active foot ulceration. 13. Severe peripheral arterial disease characterized by ischemic rest pain or severe claudication. 14. Major surgical operation within 30 days prior to screening. 15. Use of an investigational drug within 30 days prior to screening. 16. Chronic usage of any immunosuppressive medication (such as cyclosporine, azathioprine, sirolimus, or tacrolimus). 17. Bleeding disorder, treatment with warfarin, or platelet count below 50,000. 18. Allergy to Humalog or Basaglar insulin. 19. Current chronic administration of oral or parenteral corticosteroids. 20. Any life-threatening disease, including malignant neoplasms and medical history of malignant neoplasms within the 5 years prior to screening (except basal and squamous cell skin cancer). 21. Initiation or titration of any medication used to lower glucose other than insulin in the 6 weeks prior to screening (e.g. metformin or semaglutide). Participants will not be excluded if they are non-insulin glucose lowering medication at a stable dose with no plans for discontinuation or dose modification during the course of the study). A positive response to any of the questions from the Physical Activity Readiness Questionnaire (see Appendix A) with one exception: participant will not be excluded if taking a single blood pressure medication and blood pressure is controlled on the medication (blood pressure is less than 140/90 mmHg). 22. Any chest discomfort with physical activity, including pain or pressure, or other types of discomfort. 23. Gastroparesis. 24. On a very low carbohydrate diet (less than 50g per day) 25. Taking part in another diabetes or obesity-related treatment study. 26. Any clinically significant disease or disorder which, in the opinion of the Investigator, may jeopardize the participant's safety or compliance with the protocol.